An opioid receptor agonist such as morphine and the like which is used as an analgesic is very effective in a patient having cancer pain, but as a side effect, induces severe nausea, emesis, vomiting, constipation, anuresis, and itching. Various antiemetics and anti-constipation agents are clinically used, but it can not be said that any of them exhibits the sufficient effect, and an excellent side effect alleviating agent is also demanded for improving QOL of a patient.
Patent Literatures 1 and 2, and Non-patent Literature 1 describe to the effect that a morphinan derivative is effective in treating or preventing emesis and vomiting induced by an opioid μ agonist, and Non-Patent Literature 2 describes that a 6,7-saturated-7-carbamoyl-substituted-morphinan derivatives have the opioid δ receptor antagonism. However, none of them describes or suggests the present compound.    [Patent Literature 1] International Patent Application Publication WO 2004-007503    [Patent Literature 2] International Patent Application Publication WO 95/13071    [Non-Patent Literature 1] Journal of Medicinal Chemistry 41, 4177-4180 (1998)    [Non-Patent Literature 2] Chemical and Pharmaceutical Bulletin, 52 (66) 747-750 (2004)